This column describes a Michigan initiative to implement medication prescribing algorithms for schizophrenia, bipolar disorder, and major depression. The algorithms were incorporated into the electronic medical records system of a four-county community mental health system. Guideline adherence of 30 providers who treated nearly 3,000 patients was measured at mid- and endpoints of the first year. They were adherent for about a third of their patients in the first six months (32%) and more than half in the second (52%). Scores on scales measuring providers' perceptions of algorithm ease of use and usefulness were in the midrange at both time points.